The word frequently translated “repent” in Job 42:6 is used six other times in the book, and it is nowhere else translated “repent.” It is always translated (in the NKJV anyways) as “comfort” or “comforted” or “comforters.”
One of the great problems for Job is that he can find no real comfort, no true comforter. Rather then being helped, he is hounded by his comforters. The three friends gather around him to comfort him (2:11), and Job certainly was looking for comfort (7:13), but they are “miserable comforters” (16:2). After more of their accusations, Job concludes that they have tried to comfort him with empty [hebel] answers (21:34). Try as he may, Job can find no comfort. Job was once a great king who offered comfort to others in their mourning (29:25), but he has found none in his distress.
Given this narrative, it makes great sense to see Job’s final response to Yahweh’s speeches not as some kind of change of mind (i.e. repentance), especially since the Lord explicitly says that what Job spoke was right (42:7-8). Rather, it makes great sense to see Job as saying that he is finally comforted in his dust and ashes. The last use of the word is in 42:11 where his brothers and sisters come to him, eat with him, and really do comfort him. Job first finds his comfort in Yahweh, the Great Comforter, and then his brothers and sisters come and extend more of the comfort of Yahweh to Job.
The other verb in 42:6 is MA’AS which is usually translated “reject/refuse/despise.” The word is used a number of times in Job: Eliphaz exhorts Job not to reject the discipline of the Almighty (5:17), Bildad says that God will not reject the blameless (8:20), Job cries out to God asking why He despises the work of His hands (10:3), even children despise him Job says (19:18), and Elihu insists that God is just and does not randomly reject people (35:5).
The challenge with translating this verse is that it has no direct object. What does Job reject/despise/refuse? There is one other use of the same verb in Job where there is no direct object but the context fills out the meaning for us. In 7:16, Job says “I despise _____ : I would not live forever. Leave me alone for my days are but a breath.” Given the context it makes good sense for the translators to supply the words “my life.” Job says: “I despise my life: I don’t want to live forever…” And Job says something similar later in 9:21 when he insists, “I am blameless, yet I do not know myself, I despise my life.” And here the direct object “my life” is explicitly provided. The idea is that Job knows he’s blameless, but given his circumstances he does not want to live.
So my suggestion for translating 42:6 is the following:
“Therefore I despise my life but I am comforted in my dust and ashes.”
Job is still in great pain, he has lost so much of what was dear to him, and his kingdom is still in terrific jeopardy, but in those dust and ashes, in the dust and ashes of his mourning and despair, Yahweh has spoken to him. Yahweh has spoken in the midst of the storm, and therefore Job is comforted.